25 February 2025, Volume 20 Issue 1

    

• Select all
  |

Original Article
• Select
  Research of virological factors affecting the degradation of small envelope protein of hepatitis B virus

  ZHANG Baoyu, WANG Yongxiang

  Journal of Microbes and Infections. 2025, 20(1): 1-8. https://doi.org/10.3969/j.issn.1673-6184.2025.01.001

  Abstract ( ) Download PDF ( )   Knowledge map   Save

  The envelope proteins of hepatitis B virus (HBV) include large (L), middle (M) and small (S) envelope proteins, with S protein being the most abundant viral transmembrane protein. Functional cure is currently regarded as the therapeutic goal for chronic hepatitis B. One of the key indicators of functional cure is the sustained clearance of circulating hepatitis B surface antigen (HBsAg). However, the mechanisms whereby intracellular S protein is degraded remain elusive. The previous study of this research group demonstrated that G12-CAR, a chimeric antigen receptor (CAR) specifically targeting hepatitis B virus envelope proteins, inhibited S protein secretion and promoted its intracellular degradation. In this study, Huh-7 hepatoma cells transfected by different vectors expressing S protein were treated with bafilomycin A1 and bortezomib, respectively inhibiting lysosomal autophagy and proteasomal degradation pathways. Subsequently, intracellular and extracellular S proteins were detected by Western blot and enzyme-linked immunosorbent assay (ELISA). The results showed that S protein can be degraded via both lysosomal and proteasomal pathways, while other HBV components also can regulate S degradation. Both L protein and 3′-untranslated region (3′-UTR) sequences of the viral S mRNA were identified to affect intracellular S degradation. Hence, these findings may offer novel therapeutic targets for promoting HBsAg clearance.
• Select
  Research on risk factors for severe/critical COVID-19

  SUN Ruiwen, JIANG Dongfeng, SUN Yuhan, ZHAO Jingjing, WU Jing, JIN Jialin

  Journal of Microbes and Infections. 2025, 20(1): 9-15. https://doi.org/10.3969/j.issn.1673-6184.2025.01.002

  Abstract ( ) Download PDF ( )   Knowledge map   Save

  Abstract：Predicting the risk of progression to severe/critical coronavirus disease 2019(COVID-19) is crucial for optimizing clinical interventions and healthcare resource allocation. This retrospective study analyzed clinical data from 305 hospitalized COVID-19 patients admitted to Huashan Hospital between December 2022 and January 2023, aiming to identify risk factors and evaluate the predictive performance of a multifactorial model for classifying patients into severe/critical categories. Demographic characteristics, comorbidities, and laboratory parameters (including inflammatory markers, coagulation profiles, and cardiac biomarkers) were collected, with disease severity classified according to the Diagnosis and Treatment Protocol for Novel Coronavirus Infection (Trial Version 10). Multivariable logistic regression revealed that advanced age, decreased lymphocyte count, reduced hemoglobin levels, and elevated levels of C-reactive protein (CRP), interleukin-6 (IL-6), D-dimer, and brain natriuretic peptide (BNP) were independent risk factors for severe/critical classification. A combined predictive model incorporating these indicators achieved an area under the curve (AUC) of 0.748, which significantly outperformed individual predictors (AUC range: 0.625-0.681). The findings suggest that integrating age, inflammatory response, coagulation dysfunction, and cardiac injury biomarkers can effectively identify high-risk COVID-19 patients, providing a scientific foundation for early stratified management, precision treatment, and public health policymaking. This study also contributes evidence-based insights for addressing future emerging infectious disease outbreaks.
• Select
  Distribution of pathogens and risk factors of nosocomial infection in NICU neonates

  OUYANG Suhui

  Journal of Microbes and Infections. 2025, 20(1): 16-22. https://doi.org/10.3969/j.issn.1673-6184.2025.01.003

  Abstract ( ) Download PDF ( )   Knowledge map   Save

  The aim of this study was to explore the distribution of infection pathogens and drug resistance of main pathogens in neonates in neonatal intensive care unit (NICU), and to analyze the risk factors of nosocomial infection. A retrospective analysis was performed on the clinical data of 2 812 neonates in NICU of Nanjing Maternal and Child Health Hospital from January 2022 to December 2023. According to the presence or absence of nosocomial infection, neonates were divided into infection group (453 cases) and non-infection group (2 359 cases). The distribution of pathogens and drug resistance of main pathogens in infection group were analyzed. The risk factors of nosocomial infection were analyzed by Logistic regression analysis. Among 2 812 neonates in NICU, there were 453 cases (16.11%) with nosocomial infection. A total of 475 strains of pathogens were detected, mainly Gram-positive bacteria (58.32%). Among Gram-positive bacteria, coagulase-negative staphylococci had high resistance rates to penicillin C (93.57%), erythromycin (76.61%) and oxacillin (71.93%), but were sensitive to rifampin (8.19%), nitrofurantoin (1.75%), vancomycin and linezolid. Staphylococcus aureus was completely resistant to penicillin C (100%), but had no resistance to rifampicin and vancomycin. Among the gram-negative bacteria, Escherichia coli was significantly resistant to ceftriaxone (47.95%) and cefazolin (41.10%), while Klebsiella pneumoniae was highly resistant to ceftazidime (44.64%) and ceftriaxone (39.29%), but both of them were completely sensitive to imipenem and amikacin. Compared with the non-infection group, the infection group had a significantly higher proportion of infants with gestational age <37 weeks, birth weight <2 500 g, cesarean section, Apgar score ≤7 at 5 min after birth, asphyxia rescue, mechanical ventilation, parenteral nutrition, types of antibiotics ≥2, duration of antibiotic use >7 days, and length of ICU stay >7 days (P<0.05). The main pathogens of nosocomial infection are Gram-positive bacteria in NICU neonates, with high resistance rates to penicillin and erythromycin, but still sensitive to vancomycin and linezolid. Gestational age <37 weeks, low birth weight, mechanical ventilation, combined use of antibiotics and stay time in ICU >7 d are independent risk factors of nosocomial infection. It is necessary to standardize invasive operation and antibiotics management, and optimize prevention and control strategies for high-risk neonates.
• Select
  The detection rate and drug sensitivity analysis of female genital tract Mycoplasma in a regional medical center of Shanghai

  GU Junying1, ZHU Jun2, DING Li1, JI Xiaofan1

  Journal of Microbes and Infections. 2025, 20(1): 23-27. https://doi.org/10.3969/j.issn.1673-6184.2025.01.004

  Abstract ( ) Download PDF ( )   Knowledge map   Save

  The infection and drug sensitivity of Mycoplasma hominis (Mh) and Ureaplasma urealyticum (Uu) in outpatient and inpatient female patients in the Wusong area of Baoshan, Shanghai were studied to provide a scientific evidence for clinical diagnosis and treatment. Mycoplasma culture identification and count drug sensitivity kits were used to carry out Mycoplasma culture, identification and drug susceptible test. A total of 413 cases underwent Mycoplasma culture and drug sensitivity test, of which 178 cases were positive for mycoplasma culture (43.10%), 17 cases with simple Mh infection (4.12%), 152 cases with simple Uu infection (36.80%), and 9 cases with mixed infection (2.18%). In simple Mh infection, the top five high-sensitivity rates from high to low are: doxytetramycin/minocycline, josamycin, clindamycin and gatifloxacin. There is no significant difference in the sensitivity rates of the first three drugs (P>0.05). There is a significant difference between doxytetramycin/minocycline and clindamycin or gatifloxacin (P<0.05, P<0.01). The top five drug resistance rates from low to high are: doxytetramycin/minocycline, josamycin, gatifloxacin, thiamphenicol, and there is no significant difference in the resistance rate of the five drugs (P>0.05). In simple Uu infection, the top five high-sensitivity rates from high to low are: doxytetramycin/minocycline, josamycin, azithromycin and clarithromycin. The difference between the first three drugs has no statistical significance (P>0.05). The difference between doxytetramycin/minocycline and azithromycin or clarithromycin is statistically significant (P<0.01). The drug resistance rates from low to high are: doxytetramycin/minocycline, josamycin, gatifloxacin, azithromycin/erythromycin/levofloxacin, and the resistance rate of doxytetramycin/minocycline is not statistically different from the latter two drugs (P>0.05), and is statistically different from azithromycin/erythromycin/levofloxacin (P<0.05). When treating mycoplasma infections of the reproductive tract, the clinicians should try to choose minocycline, doxytetramycin or josamycin. The alternative drugs for simple Mh and Uu infections are clindamycin and azithromycin respectively.
• Select
  Diagnostic value of multiplex PCR-based targeted next-generation sequencing in invasive pulmonary aspergillosis

  ZHANG Fengxia, SHI Caiqin, WANG Wentao, ZHU Danyan, MA Nan

  Journal of Microbes and Infections. 2025, 20(1): 28-36. https://doi.org/10.3969/j.issn.1673-6184.2025.01.005

  Abstract ( ) Download PDF ( )   Knowledge map   Save

  This study evaluated the diagnostic utility of ultra-multiplex polymerase chain reaction(PCR)-based targeted next-generation sequencing (tNGS) in invasive pulmonary aspergillosis (IPA). A cohort of 209 patients clinically suspected of IPA during May and July 2023 underwent bronchoalveolar lavage fluid (BALF) collection via fiberoptic bronchoscopy. Samples were analyzed using tNGS, galactomannan (GM) assay, and Gram-stained smear. Among 209 suspected IPA cases, tNGS identified Aspergillus in 183 samples, achieving an 87.6% positivity rate. Aspergillus fumigatus was the predominant species (69.4%), followed by Aspergillus flavus (23.5%), Aspergillus terreus (3.83%), and Aspergillus niger (3.3%). GM assay, using a BALF GM index cutoff of ≥1.0, yielded a significantly lower positivity rate of 70.3% (P<0.001), but both outperformed Gram-stained smear (20.1%). Co-detection of other pathogens occurred in 168 tNGS-positive samples (91.8%). Notably, tNGS-derived Aspergillus read counts were significantly higher in GM-positive versus GM-negative patients (P<0.001). Among 15 583 BALF samples analyzed in 2023, tNGS identified Aspergillus in 2 131 (13.7%) samples. Co-pathogens were detected in 91.1% of Aspergillus-positive cases, with influenza virus (25.9%), Klebsiella pneumoniae (14.2%), Acinetobacter baumannii (12.6%), SARS-CoV-2 (12.1%), and Pseudomonas aeruginosa (9.53%) being the predominant other pathogens. This study demonstrates that tNGS surpasses the GM assay in both sensitivity and specificity for IPA diagnosis, enables precise Aspergillus species identification, and excels in detecting fungal co-infections.
• Select
  Accuracy evaluation of in vitro sensitivity test results of ceftazidime/avibactam for Klebsiella pneumoniae by disk diffusion method

  SONG Yanjie, GUO Jian, HU Liang

  Journal of Microbes and Infections. 2025, 20(1): 37-42. https://doi.org/10.3969/j.issn.1673-6184.2025.01.006

  Abstract ( ) Download PDF ( )   Knowledge map   Save

  A total of 82 strains of Klebsiella pneumoniae (KPN) clinically isolated from East Hospital Affiliated to Tongji University in Shanghai from October to December 2022 were collected in this study. Real-time fluorescent polymerase chain reaction (PCR)and enzyme inhibitor enhanced test were used to detect carbapenemase-producing genotypes of the strains. Simultaneously, the minimum inhibitory concentration (MIC) and inhibitory zone diameter of ceftazidime-avibactam (CZA) against these strains of Klebsiella pneumoniae were detected by microbroth dilution method and Kirby-Bauer disk diffusion method, respectively, to verify whether disk diffusion method could serve as a reliable alternative to the microbroth dilution method for CZA susceptibility testing. The results demonstrated complete concordance between carbapenemase genotypes (real-time PCR) and phenotypes (enzyme inhibitor enhancement test). Comparative analysis of the two susceptibility testing methods revealed high agreement between disk diffusion and microbroth dilution. The results of the two disk diffusion methods and the micro-broth dilution method revealed high agreement with categorical agreement (CA) rates of 98.3% and 99.7% and no major errors (ME ＝ 0). This study confirmed that the disk diffusion method can be used to detect the drug susceptibility of CZA to KPN. However, it still needs to be checked by broth dilution method if the inhibition zone range is within 20-22 mm.
• Select
  Clinical application of tandem dry fog hydrogen peroxide ventilator pipe disinfection device

  XU Xuguang1, HUANG Xiaoping2, CHEN Baoli3

  Journal of Microbes and Infections. 2025, 20(1): 43-47. https://doi.org/10.3969/j.issn.1673-6184.2025.01.007

  Abstract ( ) Download PDF ( )   Knowledge map   Save

  This study aimed to develop a new disinfection device for the internal tubing of ventilators and evaluate its efficacy. The tandem device was designed to disinfect the internal tubing of ventilators with hydrogen peroxide (H₂O₂) dry mist that was produced by jet technique. Forty ventilators utilized for mechanical ventilation in confirmed infectious disease cases, each with ≥72 h of continuous operation, were included in the assessment. Colony-forming units (CFU) in air intake, air outlet, and internal tubing, were determined at the following time point, before disinfection, 1 h after disinfection, and 4 h after disinfection. The eligibility criteria were CFU≤20 per sample with no detectable pathogenic bacteria. All data were subjected to statistical analysis. The qualified rate was 0% before disinfection by H2O2, while it was 100% after disinfection for 1 h and 4 h, and CFU in each detection site was significantly lower after disinfection (p＜0.05), and no pathogenic bacterial growth was detected. The tandem H₂O₂ dry mist-disinfecting device is reliable and effective, and the expected effect could be achieved by 1 h disinfection.
Case Analysis
• Select
  A case report of pulmonary infection caused by Actinobacillus ureae in a patient with malignant tumor

  WANG Le1, GUO Jian2

  Journal of Microbes and Infections. 2025, 20(1): 48-52. https://doi.org/10.3969/j.issn.1673-6184.2025.01.008

  Abstract ( ) Download PDF ( )   Knowledge map   Save

  This article presented a case of pulmonary infection caused by Actinobacillus ureae (A. ureae) in a patient with malignant tumor, along with a comprehensive literature review. During the patient’s hospitalization for chemotherapy, an opportunistic infection with A. ureae occurred, leading to typical pulmonary inflammation. The laboratory maintained consistent communication with clinicians throughout the diagnosis and treatment process, promptly conducting in vitro antimicrobial susceptibility testing on the pathogen and guiding standardized medication for the patient. Ultimately, following treatment with intravenous cefoperazone-sulbactam combined with levofloxacin for anti-infection symptomatic therapy, the patient’s pulmonary inflammation significantly improved. A literature review revealed that the infection rate of A. ureae was significantly higher than its actual detection level, suggesting that it should be considered one of the potential pathogens in susceptible patients in clinical practice. By reporting this case of pulmonary inflammation caused by an opportunistic infection of A. ureae, this article aims to raise awareness among laboratory staff about this pathogen and provide a reference for clinicians to timely diagnose and treat infections caused by rare pathogens.
• Select
  Analysis of the biological and molecular characteristics of a rare Salmonella strain in Changchun

  LI Yueting1, WU Yanli1, SONG Yanan1, TIAN Yuling2, LIU Yulan1, LI Yue1

  Journal of Microbes and Infections. 2025, 20(1): 53-58. https://doi.org/10.3969/j.issn.1673-6184.2025.01.009

  Abstract ( ) Download PDF ( )   Knowledge map   Save

  Salmonella Poona is a rare serotype of Salmonella. This study was conducted on a Salmonella strain isolated from the fecal sample of a patient reported by the active surveillance project of foodborne diseases in Changchun Children’ Hospital. Bacteriological identification, serotyping, drug sensitivity testing, and whole genome sequencing were employed to investigate its biological and molecular profiles. Results demonstrated that this strain was biochemically confirmed as Salmonella and identified as Salmonella Poona by the serological typing. The isolate exhibited resistance to most antibiotics and harbored a diverse array of resistance and virulence genes. This research confirms the first isolation of a multidrug-resistant and highly virulent Salmonella Poona strain in Changchun City, highlighting the need for heightened attention to this pathogen. This study aimed to analyze the biological characteristics and molecular features of Salmonella Poona to provide scientific evidence for clinical treatment and prevention.
Review
• Select
  Pathogenic mechanism of outer membrane proteins of Acinetobacter baumannii and its latest research progress

  LA Jiaqi1, ZHANG Xiaomeng2, LI Ru1, Chaolumenqiqige2

  Journal of Microbes and Infections. 2025, 20(1): 59-64. https://doi.org/10.3969/j.issn.1673-6184.2025.01.010

  Abstract ( ) Download PDF ( )   Knowledge map   Save

  Acinetobacter baumannii (AB), a highly pathogenic Gram-negative bacterium, exhibits remarkable environmental adaptability and prolonged survival. It can infect multiple sites in the human body and has become one of the most common pathogens in hospital-acquired infections due to its extensive acquired drug resistance, making the study of its pathogenic mechanisms urgent. Outer membrane proteins (OMPs) are among the key virulence factors of AB, contributing to adhesion and invasion, biofilm formation, immune evasion, and induction of apoptosis. In recent years, with the wide application of advanced technologies such as proteomics, transcriptomics and bioinformatics, significant progress has been obtained in the research on AB OMPs regarding structural biology, vaccine development and target identification, virulence mechanisms, and antimicrobial resistance. This review focuses on the pathogenic mechanisms of AB OMPs and the latest research advancements in this field.